This invention relates to an apparatus for detecting the operating state of a vehicle and providing the detected signal to an electronic control unit (ECU) for controlling the operation of a vehicle, and more particularly, to providing an apparatus for detecting the locking state of a buckle and generating a detected signal to facilitate the control of the operation of the vehicle.
A seat belt apparatus mounted in a vehicle is generally used to protect a driver and/or a passenger in colliding (or clashing) accidents. The seat belt apparatus includes a buckle fixed through a cable to one surface of a floor panel, and a retractor fixed to the lower portion of a center pillar with a seat belt being wound thereon. A tongue is hung at a predetermined position of the seat belt to couple with the buckle. A guider prevents twisting of seat belt when the belt is released or retreated. An anchor is used to adjust the height of the seat belt.
FIG. 1 shows a switching circuit provided with a conventional micro-switch SW1 which is mounted on the buckle to make a driver recognize the fact of whether he or a passenger wears a seat belt. The switching circuit controls the application of a power source VCC through a resistor R4 to a warning light WL mounted on an instrument panel. The warning light WL is turned on or off depending on whether the micro-switch is turned on or off, which in turn depends on the insertion of the tongue into the buckle. If the driver or the passenger occupies the seat without wearing the seat belt, the micro-switch SW1 is turned on and the warning light WL warns the driver that he is not wearing the seat belt. If the tongue is inserted into the buckle to fasten the seat belt, the micro-switch SW1 is turned off and the warning light WL is turned off to indicate that the driver is wearing the seat belt.
The switch device has a simple configuration to control the operation of the warning light mounted on the instrument panel according to the fastening or unfastening of the buckle without including any connection with a control system of a vehicle. Under such design, the control system cannot recognize the abnormal state or operation state of the vehicle. This is undesirable in view of the advancements in intelligent and automated control systems. Therefore, it is preferable if the control of all warning lights on the instrument panel is carried out by an electronic control unit (ECU) to enhance the efficiency of the vehicle control.
The switching device may cause a high voltage to discharge through the circuit in a short period of time when the switching circuit is opened or closed by the mechanical contact of the micro-switch upon the fastening or unfastening of the seat belt. This induces electromagnetic interference (EMI) that may cause damage to the ECU.
Accordingly, in order to resolve these disadvantages and problems, an object of the invention is to provide a locking state detecting apparatus of a seat belt buckle to enable an electronic control unit (ECU) to self-diagnose the control system of a vehicle.
Another object of the invention is to provide a locking state detecting apparatus of a seat belt buckle for detecting the locking state of the buckle and enabling other safety units, such as an airbag system, to cooperate with the buckle to enter a waiting mode. The safety units, such as the airbag system, can be quickly triggered into operation.
Another object of the invention is to provide a locking state detecting apparatus of a seat belt buckle for enabling a micro-stitch to detect the locking state of the buckle and to use an electronic control unit (ECU) of a vehicle control system to supply a detection signal.
Therefore, the invention is adapted to a vehicle control system for detecting an abnormal state of the vehicle, and for triggering the airbag system into operation when an abnormal state of the vehicle is detected.
In order to accomplish these objects, the invention comprises a locking state detecting apparatus of a buckle for enabling a warning light provided in an instrument panel to confirm the matter of fastening the seat belt through the turning on or off of a micro-switch, in which the buckle further comprises an electronic switch for recognizing its locking state and generating the detected signal.
In one implementation, the locking state detecting apparatus includes a micro-switch and an electronic switch assembly mounted in a buckle to cooperate with a tongue for enabling an electronic control unit (ECU) to generate a signal for the locking state of the buckle. The electronic switch assembly includes a hall sensor assembly to detect the locking state of the buckle, and a first switching element (e.g., a transistor) to turn on or off a warning light to indicate whether the seat belt is fastened. A second switching device (e.g., a transistor) is connected to the ECU through a first control resistor. The second switching device is connected to the first switching device through a second control resistor. A control voltage determined by a power supply and the hall sensor assembly is applied to the second switching device to control its operation. Depending on the operation state of the hall sensor assembly and the second switching element, the ECU can sense different amounts of resistance connected between a terminal of the ECU and ground, thereby sensing the locking state of the buckle.
In another implementation, the locking state detecting apparatus comprises a hall sensor assembly without a micro-switch. The electronic control unit ECU is connected to a switching element and a first resistor to recognize the voltage value formed by the first resistor, when the hall sensor assembly is operated. A control resistor is provided having a larger resistance value than the first resistor. The ECU identifies the voltage value formed by both the control resistor and the first resistor when the hall sensor assembly is deenergized.
In one aspect the invention features an apparatus that includes detecting means for detecting whether a seatbelt buckle is in a locked state or in an unlocked state, and a signal generating means for generating an electronic signal that can be measured by an electronic control unit of a vehicle in response to the detecting means detecting that the seatbelt buckle is in the locked state.
Implementations of the invention may include one or more of the following features.
The signal generating means includes a transistor having a first terminal, a second terminal, and a third terminal, the first terminal being electrically coupled to a first resistor, the second terminal being electrically coupled to a second resistor, and the third terminal being electrically coupled to the detecting means.
In another aspect, the invention features an apparatus that includes a seatbelt buckle, a hall sensor mounted in the buckle, and a first electronic switching device that is electrically coupled to the hall sensor.
Implementation of the invention may include one or more of the following features.
The hall sensor is responsive to a position of a tongue relative to the buckle.
The first electronic switching device includes a transistor.
The apparatus also includes a first resistor and a second resistor, the first resistor being electrically coupled to a first terminal of the first electronic switching device, the second resistor being electrically coupled to a second terminal of the first electronic switching device.
The first resistor is also electrically coupled to an electronic control unit of a vehicle.
The second resistor is also electrically coupled to a second electronic switching device.
The second electronic switching device is electrically coupled to a light emitting device.
The hall sensor includes a first terminal and a second terminal, the first terminal of the hall sensor electrically coupled to a supply voltage through a resistor, and the second terminal of the hall sensor electrically coupled to ground.
The first electronic switching device is electrically coupled to the light emitting device.
The first electronic switching device is electrically coupled to the electronic control unit through the first resistor.
In another aspect, the invention features an apparatus that includes a hall sensor mounted in a seatbelt buckle, a first electronic switching device that is electrically coupled to a first terminal of the hall sensor, and a second electronic switching device that is electrically coupled to a second terminal of the hall sensor.
Implementation of the invention may include one or more of the following features.
The first electronic switching device has a first terminal and a second terminal, the first terminal being electrically couple to a first terminal of a first resistor, the second terminal being electrically coupled to a first terminal of a second resistor.
The second electronic switching device includes a first terminal and a second terminal, the first terminal of the second electronic switching device being electrically coupled to the second terminal of the first electronic switching device, and the second terminal of the second electronic switching device being electrically coupled to ground.
Alternatively, the second electronic switching device includes a first terminal and a second terminal, the first terminal of the second electronic switching device being electrically coupled to the second resistor, and the second terminal of the second electronic switching device being electrically coupled to ground.
The apparatus also includes an electronic control unit of a vehicle that is electrically coupled to a second terminal of the first resistor.
A second terminal of the second resistor is electrically coupled to ground.
The hall sensor, the first electronic switching device, and the second electronic switching device are configured so that a voltage at the second terminal of the first resistor changes in response to a change in an output of the hall sensor.
The second electronic switching device comprises a field effect transistor (FET).
The hall sensor is responsive to a position of a tongue relative to the buckle.